Methods for extrusion of polyolefins (110) that utilize melt temperature to control molecular weight and also reduce gels. Disclosed herein is an example method for controlling polymer chain scission in an extrusion system (100), comprising: melting a polyolefin resin (110) in extruder (102) at a first melt temperature to form a first melt (112); passing the first melt (112) through a screen pack (106); forming the first melt 112) into a first polyolefin product (116, 118); melting additional polyolefin resin (110) of the same grade in the extruder (102) at a second melt temperature to form a second melt (112), wherein the second melt temperature differs from the first melt temperature by 5° C. or more to control chain scission in the extruder (102); passing the second melt (112) through the screen pack (106); and forming the second melt (112) into a second polyolefin product (116, 118).

A filter element for filtering a fluid comprises a first clamping ring with an outer ring; a first filter disk; a first inner support plate for supporting the first filter disk and which faces to the outside or to an inner flow channel; a second inner support plate provided with recesses; a second filter disk arranged adjacent the second inner support plate; and a second clamping ring which is connected to the first clamping ring by connecting elements. The filter disks and the inner support plates are arranged inside a housing which is formed by the clamping rings, by at least one outer ring and by outer support plates provided with recesses and covering the filter disks on the outside.

A filter element for filtering a fluid comprises a first clamping ring with an outer ring; a first filter disk; a first inner support plate for supporting the first filter disk and which faces to the outside or to an inner flow channel; a second inner support plate provided with recesses; a second filter disk arranged adjacent the second inner support plate; and a second clamping ring which is connected to the first clamping ring by connecting elements. The filter disks and the inner support plates are arranged inside a housing which is formed by the clamping rings, by at least one outer ring and by outer support plates provided with recesses and covering the filter disks on the outside.

There are provided a straining mechanism and a screw extruder including the straining mechanism, which can minimize material passing resistance in a breaker plate even, in a large-sized apparatus having high throughput, and which can improve the throughput by suppressing load power of the apparatus and heat generation of a material. For this purpose, a backup plate having an opening rate higher than an opening rate of a breaker plate and supporting the breaker plate is installed on a rear surface side of the breaker plate supporting a screen mesh.

There are provided a straining mechanism and a screw extruder including the straining mechanism, which can minimize material passing resistance in a breaker plate even, in a large-sized apparatus having high throughput, and which can improve the throughput by suppressing load power of the apparatus and heat generation of a material. For this purpose, a backup plate having an opening rate higher than an opening rate of a breaker plate and supporting the breaker plate is installed on a rear surface side of the breaker plate supporting a screen mesh.

Techniques involve cleaning a polymer melt, which allow volatile foreign substances and solid foreign substances to be removed from the polymer melt. Such techniques involve a filter element and a vacuum of a vacuum chamber. The polymer melt is fed through the filter element into the vacuum of the vacuum chamber, The filter element binds the solid foreign substances and the vacuum chamber takes up the volatile foreign substances.

Filtration apparatuses and screen changer devices for filtering polymeric material as well as spacer plates, and face plates for the screen changer devices and related methods are shown and described herein.

Filtration apparatuses and screen changer devices for filtering polymeric material as well as spacer plates, and face plates for the screen changer devices and related methods are shown and described herein.

A method for reducing gel in a polymer kneaded compound flowing in a polymer flow duct includes flowing a polymer kneaded compound in a polymer flow duct to a gel reduction mechanism including a gel reduction member having one or more through holes defining a squeezing flow path having a flow path cross-sectional area smaller than the polymer flow duct. The squeeze ratio S1/S2 of the squeezing flow path is 25 to 177.8, where S1 is a flow path cross-sectional area of the polymer flow duct and S2 is a sum total of flow path cross-sectional area of the squeezing flow path, to generate an extensional flow in the kneaded compound.

In one example, an apparatus for filtering a fluid (e.g., a plastic melt having impurities) includes a housing which has at least one inlet for introduction of the fluid and an outlet for delivery of the fluid and a cavity formed in the housing by wall portions of the housing for receiving a sieve support, and a sieve support which is arranged moveably in the cavity of the housing and has a longitudinal axis for receiving at least one filter element for filtering the fluid. The sieve support externally has a plurality of integrally formed raised portions and/or raised portions and/or recesses are formed at wall portions of the housing, that delimit the cavity, such that provided between the wall portion and the sieve support are a plurality of gaps/cavities, by means of which a slight fluid flow is enabled in operation. Another example concerns a valve arrangement.